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ScienceShot: Planck Satellite's First View of Universe

TURIN, ITALY—At a press briefing here this morning, the European Space Agency (ESA) released the first full-sky image of the universe's microwave radiation taken by its Planck satellite, which was launched just last year. (Here's a preview of the mission in Science.) Although it may be 2012 before the space observatory accumulates enough data to answer questions about the early universe, this initial snapshot developed from observations between August 2009 and May 2010 shows that the satellite is "very healthy, and all the instruments are working, sometimes better than expected," says Nazzareno Mandolesi, director of the Institute of Space Astrophysics and Cosmic Physics in Bologna, Italy. One of Planck's goals is to image the so-called cosmic microwave background (CMB) with unprecedented resolution. This radiation represents the first photons to escape from being tied up with matter as the universe cooled after the big bang. CMB "is the light that appeared 379,000 years after the big bang of the universe. ... It's the first light of the universe." Mandolesi says. Planck is already mapping the fine details of CMB at the edges of the sky (top and bottom of picture), but the microwave radiation from the dust and gas in the Milky Way obscures a large portion of its view (center of the map). It will take several years of data analysis to factor out the radiation from the galactic plane and get a clear full-sky picture of CMB. Once available, however, the CMB map should resolve competing theories of how the universe underwent a period of inflation after the big bang and provide other cosmological answers. The scientists responsible for the ESA satellite are being protective of the flood of data streaming back to them from space. Mandolesi notes that the image released today has had its data "degraded" so that other researchers can't easily utilize it for the time being. "We don't want to be scooped," he says. ESA plans a more comprehensive release of Planck's initial data in 2011.